WG-04: Compression

Scope

To provide data compression facilities for the DICOM standard and to advise on application or object-related definitions of data compression parts of the DICOM Standard created by other working groups.

Roadmap

Develop appropriate DICOM transfer syntaxes for new Parts of JPEG 2000 as they are released.

Short-Term Objectives

We plan to serve a maximal number of modalities and clinical situations, with support for growing areas such as telemedicine.

Current Status

Compression that is already available in the standard:

JPEG (ISO 10918-1) – all processes

lossy (DCT)

lossless

sequential, progressive

Huffman, arithmetic entropy coders

RLE (aka TIFF Packbits)

ultrasound

JPEG-LS (ISO 14495-1) (DICOM CP-174)

lossless, lossy (“near-lossless”)

JPEG 2000 Part 1 (ISO 15444-1)

JPEG 2000 Part 2 Multi-Component Transfer Syntaxes

JPEG 2000 JPEG Interactive Protocol (JPIP)

Current Work Items

None currently, but we are starting to prepare a work item for 3D image compression. We hope to start an educational effort related to compression in medical imaging in the next year.

Challenges and Opportunities

Both the user and vendor communities have an investment in current technology and may be slow in embracing new compression techniques. The issues surrounding the use of irreversible (lossy) compression in clinical environments have also been a limiting factor.